Circuitry for synchronizing a mechanical resonator

ABSTRACT

A mechanical resonator, with a pilot frequency f, is synchronized by means of an electromagnetic maintenance motor component governed by a modulated voltage generator of frequency n.f.

United States Patent 1191 Berney Mar. 19, 1974 CIRCUITRY FOR SYNCHRONIZING A [58] Field of Search 318/1 19-133; MECHANICAL RESONATOR 310/36-39; 58/23, 29; 331/116 M, 166, 159, [75] Inventor: Jean-Claude Berney, Lausanne, 172

Switzerland [56] References Cited [73] Assignee. 1533;121:1183? S. A., Lausanne, UNITED STATES PATENTS 3,292,064 12/1966 Watters 318/127 [22] Filed: Feb. 15, 1973 [21] App]. No.: 332,678 Primary Examiner-D. F. Duggan Attorney, Agent, or F irm-Waters, Roditi, and Related US. Application Data Schwartz [63] Continuation of Ser. No. 173,564, Augv 20, 1971,

abandmd 57 ABSTRACT [30] Foreign Appncation Priority Data A mechanical resonator, with a pilot frequency f, is

Ma 4 1971 Switz fland 6545/71 synchronized by means of an electromagnetic maintey e nance motor component governed by a modulated 52 us. Cl 318/128, 318/132, 58/23 voltage genemo of frequency [51 1 Int. Cl. H02k 33/02 10 Claims, 13 Drawing Figures PATENTEI] MR 191914 SHEU 1 OF 3 FIG.

F/GIZ CIRCUITRY FOR SYNCI-mONIZING A MECHANICAL RESONATOR This application is a continuation of Application Ser. No. 173,564, filed Aug. 20, 1971, now abandoned.

FIELD OF INVENTION The invention relates to electrical and electronic timing instruments and the like as well as to associated processes.

SUMMARY OF INVENTION An object of the present invention is to provide a process for synchronizing a mechanical resonator with pilot frequency f by means of an electromagnetic maintenance motor component put under the control of a modulated voltage generator at frequency n'f where n is an integer, the said resonator receiving for that purpose pulses of energy guaranteeing the maintenance of its oscillation, practically on the instant that it traverses its position of rest.

In accordance with the invention, a resonator is elastically restrained whenever it tends to exceed an angle of oscillation preset in relation to its position of rest. A modulated voltage source is made to operate at frequency nf on the control circuit of an electromagnetic maintenance motor component to obtain, as a function of the phase shift between the pilot frequency and frequency f i A f of the mechanical resonator oscillations, a change of the energy of the maintenance pulses capable of stabilizing the mechanical resonator oscillation frequency at frequencyf.

A device for putting the process of the invention into service employs a mechanical resonator in the form of an oscillating unit of the balance-wheel type. It works in conjunction with a permanent magnet and a maintenance actuating coil excited, in practice, at the instant the balance passes through its position of rest. The device is characterized by means which elastically push back the oscillating unit when its angle of oscillation tends to exceed an angle of oscillation preset in relation to its position of rest to raise its frequency from f Af to f Af. The device is further characterized by a modulated voltage source at frequency n'f controlling a semi-conductor switch in such manner that it is opened and closed alternatively during each succeeding half period of the frequency n'f, such switch being connected to the control circuit of the actuating coil of voltage V so that the voltage applicable to this latter may be alternately equal to V and V AV during each half period of maintenance pulse, the effect being to change the energy received by the resonator in terms of its phase shift. The modulated voltage source will be preferably a square-wave generator, but can also be a generator with other characteristics.

BRIEF DESCRIPTION OF DRAWING The attached drawing shows several embodiments with variations in the mechanical and electrical components of the device, given by way of illustration. In the drawing:

FIG. 1 is a vertical section taken axially of the mechanical portion according to a first embodiment;

FIG. 2 is a plan view of the structure of FIG. 1;

FIG. 3 is a diagram of an electrical portion according to a first embodiment of the invention;

FIG. 4 is a curve relating to the oscillation of the mechanical resonator;

FIG. 5 illustrates the distribution of actuating pulses transmitted according to FIG. 3, to the mechanical portion shown in FIGS. 1 and 2;

FIGS. 6 and 7 illustrate second and third electrical portions in accordance with further embodiments; and

FIGS. 8 through 13 illustrate very diagrammatically three embodiments which differ in the mechanical portion from the first embodiment.

DETAILED DESCRIPTION In FIGS. 1 and 2 is illustrated the synchronizing of the oscillation frequency of a mechanical resonator 1, constituted by a balance wheel rotating on shaft 2, with electrical actuating pulses of given pilot frequency f, transmitted to the winding of an actuating coil 3.

For this purpose, the resonator 1 carries a permanent magnet 4, and is further connected to a spiral spring 5 in the same way as is known for clockwork balance wheels.

The magnet 4 is so arranged that when the resonator is at rest it stands between the poles 6 of the electromagnet formed by the aforesaid actuating coil and its core 7.

Said resonator 1 also carries a peg 8 which, on each swing to both sides of its position of rest, hits a leaf spring 9 carried by a terminal stud 9' set in a bridge 10 supporting one of the bearings 11 of the shaft or arbor 2, whose other bearing 12 is located in the plate 13.

If, during operation, the resonator tends to exceed an oscillation amplitude of 180 from its resting position, the peg 8 hits the leaf spring 9 once per semi-oscillation and said leaf resists the peg and instantaneously changes the oscillation frequency of the resonator, which tends in practice to oscillate between the frequencies f i Af.

The acceleration to frequency f Af communicated to it by leaf spring 9 appears in the frequencyamplitude curve of FIG. 4, whose a ordinates correspond to amplitude and whose abscissae F correspond to the frequency, which increases suddenly on the pegs meeting with the leaf spring.

The movement of magnet 4 in respect to poles 6 is put out of phase with reference to the oscillation frequency during the operation.

Core 7 carries, as can be seen, a second coil 14 designated as the interceptor coil since on each crossing of magnet 4, the latter induces in it a current whose phase shift, duration and characteristics are dependent on the oscillation frequency of the resonator.

In FIG. 3, the coils 3 and 14 again appear at B3 and B14. The control circuit of the maintenance motor element is supplied at successive half periods with current provided by an oscillator (not shown) generating square waves 15 of frequency f, by means of a semiconductor switch formed by the transistor T3 connected to a source of voltage +V and on whose base the voltage 15 acts. The control circuit composed of coil B14, capacitor C, resistor R and transistor T14 forms part of an arrangement known in watch-making for the maintenance of balance wheel oscillations.

In the present case, the idea is to correct a frequency F AF tosynchronize it with pilot frequency f. For that reason the pulses emitted by the collector of transistor T3 travel through the collector of second transistor T14 whose emitter is connected to coil B3 and coil B14, which transmitsto it the induced pulses. Its collector is further connected to voltage +V through a diode D.

Starting with the pilot signal arising from the maintenance pulses 15, each semi-period will in turn make the transistor T3 conductive or on the contrary will block it. During the half period in which it is conductive, it short-circuits diode D.

When, on the other hand, the induced voltage in interceptor coil B14 makes the transistor T14 conductive, the actuating coil B3 receives practically the whole voltage V if the transistor T3 is conductive or a voltage V Vd if the transistor T3 is blocked, Vd being the voltage drop in the diode.

It follows from this that the maintenance energy supplied by the actuator coil B3 to resonator 1 from the pulse generator 15 will depend first of all on the phase shift between the pulsation of interceptor coil B14 and the pilot signal 15 of frequency f, applied to transistor T3. FIG. shows what happens.

The top part of FIG. 5 shows the shape of the square pulses of frequency f and its lower part shows the shape of the actuating pulses actually transmitted to coil B3. Of these last pulses, the one marked 16 corresponds to the normal run in the synchronization state.

The pulse induced in the interceptor coil is in this case produced at the very instant when the curve 15, passes the transistor T3 from the dormant state to that of conductivity. In conformity with what has been said above, just before this passage, the maintenance energy corresponds to voltage V Vd and, just after, to the voltage V. This amount of energy will be that which would correspond to the maintenance of the ideal resonator of frequencyf.

If, for example, after having come in contact with the leaf spring 9, that frequency increases by reason of the acceleration transmitted to the resonator, the signal emitted by coil B14 will be ahead at the instant the inversion of the properties of transistor T3 takes place. The motive energy transmitted, diode D being out of circuit, will be supplied under voltage V Vd solely (curve 17). Therefore, it is less than in the preceding case, allowing the resonator to slow down to lessen its frequency.

If, on the contrary, that frequency falls below f, the coil B14 signal will be transmitted late, namely at the instant when the full voltage V can be transmitted to the actuator coil B3 (curve 18). Acceleration will then occur.

Through this action, corrections will be steadily effected and a balanced state of synchronism will be established between the motor (pulse and the resonator (oscillating unit 1).

From the electrical as well as the mechanical viewpoint, the same result can be obtained by use of other layouts and arrangements, as shown hereunder.

FIG. 6 relates to a second embodiment of the electrical portion which makes use of the Zener diode effect.

The square pilot pulses 15 are again applied to transistor T3. The actuator and interceptor coils are shown again at B3 and I314. The emitter of transistor T3 is connected directly to coil B3 and its collector to a Zener diode Z. This diode is made conductive or dormant as in the preceding example. This variation, in

voltage V or to a reduced voltage V V where V represents the voltage drop in diode Z.

The release of the efiective motor pulses is operated here as in the first example through the coil B14 acting on the transistor T14 and the subsequent phenomena are identical with those which have just be described.

The third embodiment of the electrical equipment is shown in FIG. 7. It uses a single junction transistor T3, the motor pulses being in this coil saw-toothed.

The references in FIG. 7 are generally the same as in the prior embodiments for denoting the same components as in the preceding two embodiments, V being in this embodiment the drop in voltage in the singlejunction transistor T3.

The phenomena which develop in this embodiment are exactly the same as described above, namely that, according to the correction to be made, the motor coil B3 will be subjected to the full voltage V or to a reduced voltage V V The pilot pulses 15' could, it should be noted, have other shapes.

Beyond the above-described electrical layouts, which do not exhaust all the possibilities with the scope of the invention, there are next described three other embodiments characterized by modification of the mechanical portion.

Instead of attaching the left spring to the permanent frame of the device, it can be attached to the resonator and made to abut against a fixed member of the device as shown in FIGS. 8 and 9.

Here, the oscillating-resonator 19 carries and takes with it the flexible leaf spring 20 which, as shown in FIG. 9, impinges on a pin 21 fastened to the frame of the device.

In the embodiments according to FIGS. 10 and 11, two magnets 22 and 23 are used, the former being borne and carried along by the oscillating resonator 24 and the other being fixed.

These magnets are so arranged that at a given angle of oscillation of the resonator they tend to meet one another but are mutually repelled (FIG. 11). This repulsion obtains results similar to those exerted by a flexible leaf spring.

In still a further embodiment as shown in FIGS. 12 and 13, a spiral spring 25 (for example, corresponding to spring 5 in FIGS. 1 and 2) has the play of its outside turn limited by two pins 26 and 27 so that at a given moment its motion is stopped and it is repelled (FIG. 13).

Similarly, all electromechanical devices allowing the oscillations of a mechanical resonator to be maintained, together with the control circuits associated therewith, can be used including systems of control by push buttons.

What is claimed is:

l. A controlled oscillating device comprising a resonator in the form of a balance-wheel type oscillating unit having a position of rest and being angularly oscillatable therefrom, a permanent magnet on said resonator and having a path of movement established thereby, magnetic poles adjacent said path, an interceptor coil associated with said poles and excited when the resonator passes through said position of rest, means elastically repelling said resonator when its angle of oscillation tends to exceed a predetermined angle of oscillaturn, causes coil B3 to be subjected to either the full tion relative to its rest position to raise the frequency thereof from f Af to f Af, means to produce a voltage of a frequency nf, a semiconductor switch including a voltage dropping element and controlled by the latter said means so that the switch is alternately opened and closed during each succeeding half period of the voltage of frequency n-f, an actuating coil associated with said interceptor coil and poles, and a control circuit for the actuating coil and including a semiconductor element coupled to said interceptor coil, said switch being connected to the control circuit of the actuating coil so that the voltage applicable to said actuating coil is controllably equal to V and V AV due to the operation of said voltage dropping element during each said half period whereby to change the energy received by the resonator in terms of its phase shift.

2. A device as claimed in claim 1 wherein said voltage dropping element is a diode between the voltage source and the control circuit and wherein the semiconductor switch includes a semi-conductor connected in parallel to said diode.

3. A device as claimed in claim 1 wherein the semiconductor switch includes a semi-conductor element series-connected with the first said semi-conductor element.

4. A device as claimed in claim 1 wherein said voltage dropping element is a Zener diode and wherein the semiconductor switch includes a semi-conductor series-connected to said Zener diode.

5. A device as claimed in claim 1 wherein the semiconductor switch includes a single-junction type transistor as the voltage dropping element.

6. A device as claimed in claim 1 comprising a fixed elastic body and wherein the oscillating unit includes a stop which impinges on said elastic body at said predetermined angle.

7. A device as claimed in claim 1 comprising a fixed stop and wherein the resonator includes an elastic body which hits said stop at said predetermined angle.

8. A device as claimed in claim 1 comprising a fixed permanent magnet and wherein the resonator includes a permanent magnet which, at said predetermined angle, encounters said fixed permanent magnet to be repelled thereby.

9. A device as claimed in claim 1 comprising a spiral spring, and spaced abutments, the resonator being connected to said spiral spring, and having a play which is limited by said abutments.

10. A controlled oscillating device comprising a mechanical oscillating means having a characteristic frequency of oscillation f, a permanent magnet on said oscillating means and having a path of movement established thereby, magnetic poles adjacent said path, an interceptor coil associated with said poles and excited when said magnet passes said poles, stop means elastically repelling and changing the frequency of oscillation of said oscillating means when the latter exceeds a predetermined angle of oscillation, an actuating coil operatively associated with said interceptor coil and poles and adapted to impart energy via said poles to said magnet, means to produce an oscillating voltage of frequency n'f, voltage generating means for supplying an actuating voltage for said actuating coil, a semiconductor switch means including a voltage dropping element for reducing said actuating voltage, a semiconductor controlled by said interceptor coil, said semi-conductor switch means being controlled by said oscillating voltage of frequency n-f for the selective decreasing of said actuating voltage depending on the phase relationship between the excitation of said interceptor coil and said oscillating voltage. 

1. A controlled oscillating device comprising a resonator in the form of a balance-wheel type oscillating unit having a position of rest and being angularly oscillatable therefrom, a permanent magnet on said resonator and having a path of movement established thereby, magnetic poles adjacent said path, an interceptor coil associated with said poles and excited when the resonator passes through said position of rest, means elastically repelling said resonator when its angle of oscillation tends to exceed a predetermined angle of oscillation relative to its rest position to raise the frequency thereof from f - Delta f to f + Delta f, means to produce a voltage of a frequency n.f, a semiconductor switch including a voltage dropping element and controlled by the latter said means so that the switch is alternately opened and closed during each succeeding half period of the voltage of frequency n.f, an actuating coil associated with said interceptor coil and poles, and a control circuit for the actuating coil and including a semi-conductor element coupled to said interceptor coil, said switch being connected to the control circuit of the actuating coil so that the voltage applicable to said actuating coil is controllably equal to V and V - Delta V due to the operation of said voltage dropping element during each said half period whereby to change the energy received by the resonator in terms of its phase shift.
 2. A device as claimed in claim 1 wherein said voltage dropping element is a diode between the voltage source and the control circuit and wherein the semi-conductor switch includes a semi-conductor connected in parallel to said diode.
 3. A device as claimed in claim 1 wherein the semiconductor switch includes a semi-conductor element series-connected with the first said semi-conductor element.
 4. A device as claimed in claim 1 wherein said voltage dropping element is a Zener diode and wherein the semiconductor switch includes a semi-conductor series-connected to said Zener diode.
 5. A device as claimed in claim 1 wherein the semi-conductor switch includes a single-junction type transistor as the voltage dropping element.
 6. A device as claimed in claim 1 comprising a fixed elastic body and wherein the oscillating unit includes a stop which impinges on said elastic body at said predetermined angle.
 7. A device as claimed in claim 1 comprising a fixed stop and wherein the resonator includes an elastic body which hits said stop at said predetermined angle.
 8. A device as claimed in claim 1 comprising a fixed permanent magnet and wherein the resonator includes a permanent magnet which, at said predetermined angle, encounters said fixed permanent magnet to be repelled thereby.
 9. A device as claimed in claim 1 comprising a spiral spring, and spaced abutments, the resonator being connected to said spiral spring, and having a play which is limited by said abutments.
 10. A controlled oscillating device comprising a mechanical oscillating means having a characteristic frequency of oscillation f, a permanent magnet on said oscillating means and having a path of movement established thereby, magnetic poles adjacent said path, an interceptor coil associated with said poles and excited when said magnet passes said poles, stop means elastically repelling and changing the frequency of oscillation of said oscillating means when the latter exceeds a predetermined angle of oscillation, an actuating coil operatively associated with said interceptor coil and poles and adapted to impart energy via said poles to said magnet, means to produce an oscillating voltage of frequency n.f, voltage generating means for supplying an actuating voltage for said actuating coil, a semi-conductor switch means including a voltage dropping element for reducing said actuating voltage, a semi-conductor controlled by said interceptor coil, said semi-conductor switch means being controlled by said oscillating voltage of frequency n.f for the selective decreasing of said actuating voltage depending on the phase relationship between the excitation of said interceptor coil and said oscillating voltage. 